Children with normal intelligence and poor school performance, particularly in reading, present significant problems in etiology and the development of effective remedial techniques. Longitudinal data collected in the CPP on a population of 40,000 seven year old children permit a study to be made of early events, beginning in the prenatal period, which differentiate between children with learning disorders in the first and second grades and those without a significant discrepancy between intellectual ability and school performance. The accurate identification of precursors of behavior patterns identified as learning disorders will facilitate prevention, early diagnosis and treatment. In this study, a child is considered to have a learning disorder if he has an IQ of 90 or above on the Wexchsler Intelligence Scale for children and is more than one year beow grade expectancy (actual grade placement) in reading or spelling on the Wide Range Achievement Test. Preliminary findings indicate that when compared with control groups matched for IQ, children with learning disorders had families of lower socio-economic status as indicated by parental education, occupation and income. Mothers of children in the learning disorder groups were of higher parity, had received less prenatal care and were more frequently unmarried. The children themselves were more frequently male, and among Negroes, tended to be smaller than controls during early childhood. Speech was less well developed at age three and psychological test scores, including IQ, were lower at age four. Hyperactivity and shorter attention span, as well as less verbal communication were also evident at age four. Similar findings emerged at age 7 even though the learning disorder groups and their controls were matched for IQ at this age.